Question 4. Give main features of each computer generation.

Answer:

Computer Generation: Computer have classified on five generations on the basis of size, efficiency, speed, power and memory. These are

1. First Generation Computers: 1946 – 1958 (vacuum Tubes).  Some of the main features of first generation computers are listed below.  
   • Vaccuum Tubes were used
   • Computers were slow, expensive and often unreliable 
   • Computers took a lot of space and produce alot o heat. e.g ENIAC and UNIVAC are first generation computers.

   

2. Second Generation Computers: 1959 – 1964 (Transistors).  Some of the main features of second generation computers are listed below.
   • Transistors are used in second generation computer.
   • Transistors were faster, smaller, cheaper and more reliable than vacuum tubes.
   • One transistor replaced 40 vaccuum tubes.
   • Assembly language was used in second generation computer.

   

3. Third generation computer: 1965 – 1970 (Integrated Chips) Some of the main features of third generation computers are listed below.
   • Integrated circuits were used.
   • ICs increased the speed and efficiency of computer
   • A huge amount of transistors are mounted on ICs, increased speed and performance ;
   • ICs reduced the size and cost of computer.

   

4. Fourth Generation Computer: 1971 - Today
   • Microprocessor were used.
   • Millions of Transistors are mounted over single chip
   • Increased overall performance, speed and efficiency of computer
   • ICs reduced the size and cost of computer.

   

5. Fifth Generation Computer: Present – Future
   • Fifth generations computer are still in development phase.
   • Artificial intelligence are used
   • Robots are example of 5th generation computer
   • Main objective of 5th generation computer are to build enough intelligent computer to respond to natural language.

   

Question 5. Explain different types of digital computers.

Answer:

Types of digital computer On the basis of computer size, speed and performance digital computers are classified into four classes

1. Super Computer:

         Super computer are largest in size and the most powerful computers. It is used in large laboratories and government organization where a lot of processing speed and memory are required. These computers are expensive and their speed is measured in TIPS (Trillion instructions per second. i.e Columbia SC

2. MainFrame Computers:

         After Super Comuters, the most expensive, largest and the most speedy computer are mainframe computers. Such computers are used in large companies and organization etc. the computer can control and supervise hundreds users at a time. Computer Speed is measured in BIPS (Billions instructions per second). Such computer are used in places where huge amount of data processing is required

3. Mini Computers:

         Mini computers are smaller than mainframe. Mini computers speed is measured in MIPS (Millions instruction per second). Minicomputer speed and memory are less than mainframe. Mini computers are used in small type business and organizations

4. Microcomputers:

         Microcomputers are small in size and cost. Such type of computers are mostly used by common users. Microcomputers Speed are measured in BIPS (Billions instruction per seconds) i.e Laptop computers, desktop Computers etc